Dual fan assembly

ABSTRACT

A dual fan assembly includes two fans connected to a motor casing and a synchronous motor is received in the motor casing and has an eccentric output shaft. A connection unit includes a shaft which extends through the motor casing and is connected to the seat. A rotation mechanism received in the motor casing has a rotatable member mounted to the shaft and a curved member which is located outside of the rotatable member and two ends of the curved member are respectively connected to a rotatable member and a link which is connected with the output shaft of the synchronous motor. By the rotation mechanism, the motor casing is reciprocally rotated a range of angles and the two fans are moved with the rotation of the motor casing.

FIELD OF THE INVENTION

The present invention relates to a dual fan assembly wherein the motor casing is rotated reciprocally within a range of angles and two fans are connected to the motor casing so as to form breezing feature.

BACKGROUND OF THE INVENTION

A conventional dual fan assembly is shown in FIG. 8 and generally includes a motor casing 70 and two fans 80 are connected to a connection portion 72 of the motor casing 70 by two link sets 81. The motor casing 70 is connected to a rod which is fixed to the ceiling. An electrical unit 73 and a rotation activation unit 74 are received in the motor casing 70. The rotation activation unit 74 includes a synchronous motor 741 and a gear set 742. The two fans 80 is activated by the power provided by the electrical unit 73 so that the blades of the two fans 80 rotate and simultaneously, the connection portion 72 is rotated by the rotation of the blades of the two fans 80 so that the two fans 80 are rotated about the rod 71. The speed can be limited within an acceptable range by the cooperation of the synchronous motor 741 and the gear set 742. However, it is noted that the electrical unit 73 includes carbon brushes which are exposed and easily oxidized which causes poor contact and affects the electrical power to be supplied to the fans 80. The brush seats 731 and the copper-made rings 732 of the brushes need to be replaced every a period of time. The whole set of the dual fan assembly is so heavy and the replacement for the brush seats 731 and the copper-made rings 732 is not convenient for the maintainers.

The present invention intends to provide a dual fan assembly which includes a simple structure and the motor casing is reciprocally rotated within a range of angles so as to move the two fans within a desired range of angles.

SUMMARY OF THE INVENTION

The present invention relates to a dual fan assembly which comprises a motor casing having a connection tube located therein and a rod is connected between the motor casing and a ceiling. A synchronous motor is received in the motor casing and has an eccentric output shaft. A connection unit has a seat securely mounted on the rod and a shaft extends through the motor casing and connected to the seat. A rotation mechanism has a rotatable member mounted to the shaft and located beneath the seat. A curved member is located outside of the rotatable member and has a first end pivotably connected to the rotatable member, the other end of the curved member is pivotably connected to a link. The link is connected with the output shaft of the synchronous motor. A light unit is connected to a lower end of the shaft and two fans are connected to the motor casing by two respective connection link sets.

The primary object of the present invention is to provide a dual fan assembly wherein the rotation mechanism in the motor casing includes less number of parts and does not need any electrical components so that it is easily to be maintained. The motor casing reciprocally rotates an angle so that the two fans connected to the motor casing move with the motor casing so as to provide breezing feature.

The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the dual fan assembly of the present invention;

FIG. 2 is an exploded view to show the main parts of the dual fan assembly of the present invention;

FIG. 3 is a perspective view to show the rotation mechanism in the motor casing of the dual fan assembly of the present invention;

FIG. 4A is a cross sectional view along line A-A in FIG. 3;

FIG. 4B is a cross sectional view along line B-B in FIG. 3;

FIGS. 5A, 5B and 5C respectively show that the motor casing rotates three different angles;

FIGS. 6A, 6B and 6C respectively show the rotation mechanism at the positions in FIGS. 5A, 5B and 5C;

FIG. 7 shows that the two fans can be pivoted an angle, and

FIG. 8 is a cross sectional view to show a conventional dual fan assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1, 2, 3, 4A and 4B, the dual fan assembly of the present invention comprises a motor casing 20 having a connection tube 21 located therein and a rod 10 having a first end connected to a suction member 11 which is fixed to a ceiling, and a second end of the rod 10 is connected to connection tube 21 of the motor casing 20. The connection tube 21 includes a lower flange 22 and a higher flange 23, both of which enclose a through hole 25 defined in the connection tube 21 and a curved slot 24 is defined in a top of the higher flange 23.

A synchronous motor 27 is received in the motor casing 20 and has an eccentric output shaft 28 which extends through a hole 26 defined through the motor casing 20. A connection unit 30 has a seat 31and a shaft 32. The seat 31 is securely mounted on the rod 10 and the shaft 32 extends through the through hole 25 in the connection tube 21 of the motor casing and is connected to the seat 31. The seat 31 is connected with a top plate 12 to seal an open top of the motor casing 20. Two bearings 33, 34 are mounted on the shaft 32.

A rotation mechanism 40 is received in the motor casing 20 and includes a rotatable member 41, a curved member 42 and a link 43. The rotatable member 41 is mounted to the shaft 32 and located beneath the seat 31. A light unit 50 is connected to a lower end of the shaft 32. An extension 411 is radially connected to the rotatable member 41 and includes a first aperture 412 and a second aperture 413. A pivot 414 extends through the first aperture 412 and is movably inserted into the curved slot 24 of the connection tube 21. The curved member 42 is located outside of the rotatable member 41 and has a first end thereof pivotably connected to the second aperture 413 and a second end of the curved member 42 is pivotably connected to the link 43. The link 43 has a through hole 431 in one end and the other end of the link 43 has a protrusion 432 which is connected to the second end of the curved member 42. The output shaft 28 is pivotably connected to the through hole 431 so as to be connected to the link 43. Two fans 60 are connected to the motor casing 20 by two respective connection link sets 29.

Referring to FIGS. 5A, 5B, 5C, 6A, 6B and 6C, when the output shaft 28 of the synchronous motor 27 drives the link 43, the curved member 42 is pivoted and move the pivot 414 in the curved slot 24 so that the motor casing 20 is rotated in an angle “θ as shown in FIGS. 5B and 6B. When the motor casing 20 rotates to the angle “θ′” as shown in FIG. 5C and 6C, the link 43 is pivoted about the output shaft 28 and the curved member 42 is pivoted to a limit position, when the link 43 is continuously pivoted, the curved member 42 is pivoted in opposite direction and the motor casing 20 rotates to its original position. Therefore, the motor casing 20 can rotated reciprocally within a range of angles and the two fans 60 swing with the motor casing 20 to provide breezing feature. In other words, the motor casing 20 does not rotate 360 degrees. The two fans 60 can also pivoted an angle relative to the horizontal plane as shown in FIG. 7 when needed.

The rotation mechanism 40 does not include any electrical component and has less number of parts so that it is easily to be maintained.

While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention. 

1. A dual fan assembly comprising: a rod having a first end adapted to be fixed to a ceiling; a motor casing having a connection tube located therein and a second end of the rod connected to connection tube of the motor casing,; a synchronous motor received in the motor casing and having an eccentric output shaft; a connection unit having a seat and a shaft, the seat securely mounted on the rod and the shaft extending through the motor casing and connected to the seat; a rotation mechanism having a rotatable member, a curved member and a link, the rotatable member mounted to the shaft and located beneath the seat, the curved member located outside of the rotatable member and having a first end pivotably connected to the rotatable member, the other end of the curved member pivotably connected to the link, the link connected with the output shaft of the synchronous motor; a light unit connected to a lower end of the shaft, and two fans connected to the motor casing by two respective connection link sets.
 2. The assembly as claimed in claim 1, wherein a suction member is connected to a first end of the rod.
 3. The assembly as claimed in claim 1, wherein the connection tube in the motor casing has a through hole through which the shaft extends.
 4. The assembly as claimed in claim 1, wherein the connection tube includes a lower flange and a higher flange, a curved slot is defined in a top of the higher flange.
 5. The assembly as claimed in claim 1, wherein the a hole is defined through the motor casing and the output shaft of the synchronous motor extends through the hole.
 6. The assembly as claimed in claim 1, wherein the seat is connected with a top plate to seal an open top of the motor casing.
 7. The assembly as claimed in claim 1, wherein two bearings are mounted on the shaft.
 8. The assembly as claimed in claim 1, wherein an extension is radially connected to the rotatable member and includes a first aperture and a second aperture.
 9. The assembly as claimed in claim 8, wherein a pivot extends through the first aperture and is movably inserted into the curved slot of the connection tube.
 10. The assembly as claimed in claim 1, wherein the curved member has the first end thereof pivotably connected to the second aperture and the second end of the curved member is pivotably connected to the link.
 11. The assembly as claimed in claim 1, wherein the link has a through hole in one end and the other end of the link has a protrusion which is connected to the second end of the curved member, the output shaft is pivotably connected to the through hole. 